Piriformis syndrome causes pain or numbness in your butt, hip or upper leg. It occurs when the piriformis muscle presses on the sciatic nerve. The condition may be caused by injury, swelling, muscle spasms or scar tissue in the piriformis. Most episodes go away in a few days or weeks with rest and simple treatments.
The piriformis is a flat, narrow muscle. It runs from your lower spine through your butt to the top of your thighs. Your piriformis muscle extends to each side of your body and aids in almost every movement of your lower body.
The sciatic nerve most commonly runs underneath the piriformis. The nerve travels from your spinal cord, through your buttocks, down the back of each leg, to your feet. It’s the longest, largest nerve in your body.
Although the conditions are sometimes related and both affect the sciatic nerve, they are different.
A herniated disk or spinal stenosis can cause sciatica. The symptoms tend to affect the lower back and can travel down through the buttocks and leg.
Piriformis syndrome only involves the piriformis muscle pressing on one area of the sciatic nerve in the buttock. It can feel a lot like sciatica but in a more specific area.
What causes piriformis syndrome?
Anything that makes the piriformis press on the sciatic nerve can cause piriformis syndrome.
The most common piriformis syndrome causes are:
- Inflammation (swelling) in the piriformis or the tissues around it.
- Muscle spasms.
- Scarring in the muscle.